Experimental And Mechanism Study On CO 2 Adsorption Purification Of Coal-fired Flue Gas

Adsorption is one of the common methods to remove pollutants from coal-fired flue gas.Firstly,the adsorption properties and regeneration characteristics of SO₂,NO and CO₂ on different adsorbents were studied through single component gas adsorption experiment.Secondly,multi-components gas adsorption was studied,the competitive adsorption mechanism of the multi-components gas was revealed.Subsequently,the solid amine adsorbent was prepared using the impregnation method and the adsorption of CO₂ was studied,the optimum conditions for the preparation of solid amine adsorbent were obtained,and the suitable conditions for the regeneration of CO₂ were proposed.In this article,the following results are obtained.（1）Zeolite and activated carbon are suitable for the removal of SO₂ and NO from coal-fired flue gas.According to the adsorption performance evaluation and the BET characterization,it can be seen that the texture characteristics of adsorbents are not the main factors that affecting the adsorption performance of SO₂,NO and CO₂.The thermal desorption analysis of adsorbents show that the physical adsorption is the main adsorption state on activated carbon,zeolite and mesoporous alumina for SO₂ and CO₂.There exists obvious chemically adsorbed NO on zeolite.（2）The different gas components have different effects on adsorbents.The adsorption of NO and SO₂ on 13 X zeolite is mutual inhibition,for the same adsorption sites lead to the competitive adsorption.NO promotes the SO₂ adsorption and SO₂ inhibits the NO adsorption on activated carbon.The adsorption capacity of SO₂ increases because of the oxidation promotion of NO,but the adsorption capacity of NO decreases for the same adsorption sites with SO₂,The addition of CO₂ inhibits the SO₂ adsorption and promotes the NO adsorption on both of the adsorbents 13 X zeolite and activated carbon.（3）The texture characteristics of the carrier and the loading amount of organic amines are the important factors that affecting CO₂ adsorption.The optimum loading amount of organic amines increases with the carrier pore volume.From the results of solid amine adsorbent thermal stability investigation,it can be concluded that the tetraethylenepentamine begin to volatilize at 100℃,so the regeneration temperature of CO₂ should be lower than 100℃.H2 O and SO₂ promote the CO₂ adsorption,while NO inhibits the CO₂ adsorption.The results of the regeneration experiment show that extending the time from 50℃ to 70℃ temperature range in the regeneration process is benefit for the regeneration efficiency.